Frequency of LCT -13910C>T single nucleotide polymorphism associated with adult-type hypolactasia/lactase persistence among Brazilians of different ethnic groups.

BACKGROUND: Adult-type hypolactasia, the physiological decline of lactase some time after weaning, was previously associated with the LCT -13910C>T polymorphism worldwide except in Africa. Lactase non-persistence is the most common phenotype in humans, except in northwestern Europe with its long history of pastoralism and milking. We had previously shown association of LCT -13910C>T polymorphism with adult-type hypolactasia in Brazilians; thus, we assessed its frequency among different Brazilian ethnic groups. METHODS: We investigated the ethnicity-related frequency of this polymorphism in 567 Brazilians [mean age, 42.1 +/- 16.8 years; 157 (27.7%) men]; 399 (70.4%) White, 50 (8.8%) Black, 65 (11.5%) Brown, and 53 (9.3%) Japanese-Brazilian. DNA was extracted from leukocytes; LCT -13910C>T polymorphism was analyzed by PCR-restriction fragment length polymorphism. RESULTS: Prevalence of the CC genotype associated with hypolactasia was similar (57%) among White and Brown groups; however, prevalence was higher among Blacks (80%) and those of Japanese descent (100%). Only 2 (4%) Blacks had TT genotype, and 8 (16%) had the CT genotype. Assuming an association between CC genotype and hypolactasia, and CT and TT genotypes with lactase persistence, 356 (62.8%) individuals had hypolactasia and 211 (37.2%) had lactase persistence. The White and Brown groups had the same hypolactasia prevalence (approximately 57%); nevertheless, was 80% among Black individuals and 100% among Japanese-Brazilians (P < 0.01). CONCLUSION: The lactase persistence allele, LCT -13910T, was found in about 43% of both White and Brown and 20% of the Black Brazilians, but was absent among all Japanese Brazilians studied.

Matrix metalloproteinase-9 is consistently expressed in Hodgkin/Reed-Sternberg cells and has no impact on survival in patients with Epstein-Barr virus (EBV)-related and non-related Hodgkin lymphoma in Brazil.

Clinical and histological features of classical Hodgkin lymphoma (cHL) are primarily due to the effects of cytokines and enzymes produced by Hodgkin/Reed-Sternberg (HRS) cells and their surrounding inflammatory cells. In EBV-related cancers, the expression of viral latent membrane protein 1 correlates with an increased MMP9 expression. In this study, we evaluated the prognostic relevance of MMP9 expression and EBV status in HRS cells in patients with cHL in Brazil. We selected 97 patients with cHL for EBV and MMP9 detection. EBV was detected in 52.5%, and MMP9 expression positivity was found in 87.6%. Of all cases, there was no correlation between MMP9 expression and EBV status. Response to treatment and relapse rate was independent of MMP9 expression and EBV status. MMP9 positivity did not influence overall survival and event-free survival. The consistent and increased intensity of MMP9 expression in HRS cells make this enzyme a potential target for therapy.

Increased expression of CD4+CD25 +FOXP3+ regulatory T cells correlates with Epstein-Barr virus and has no impact on survival in patients with classical Hodgkin lymphoma in Brazil.

The tumor microenvironment of classical Hodgkin lymphoma (cHL) is clearly responsible for the maintenance of the malignant Hodgkin-Reed-Sternberg (HRS) cells, and Epstein-Barr virus (EBV) has been shown to play a role in this immune evasion. EBV can increase the migration of CD4(+)CD25(+)FOXP3(+) lymphocytes, named regulatory T cells (Tregs). In this study, we assessed the distribution and biological significance of Tregs in patients with cHL. Tissue microarrays were constructed using diagnostic biopsies available in 130 cHL patients and stained with CD4, CD8, CD25, and FOXP3 antibodies. For the present study, only cHL patients whose histology could be confirmed and EBV association established were studied. From the 130 cHL patients selected for this study, 56 were classified as EBV-related and 74 EBV non-related cHL. There were no association between clinical characteristics and the expression of Tregs. However, higher levels of Tregs correlated with EBV presence on HRS cells (p = 0.02), although it did not influence event-free survival (EFS) and overall survival (p = 0.98 and p = 0.59, respectively). This study demonstrates that Tregs expression correlates with EBV presence in HRS cells and has no impact on survival of patients with cHL. Further studies investigating the mechanisms in which EBV recruits Tregs to the tumor microenvironment will contribute not only to our understanding on the pathogenesis of cHL but also to the development of new therapeutic strategies.